The trend in mining and mining equipment supplies is to reduce the numbers of mine workers needed to operate equipment and perform tasks, and at the same time increase productivity. In many equipment areas of mining operations this is being achieved. However, to date, the automation of roof bolting has been relatively slow due to particular complications and difficulties which are peculiar to the roof bolting process.
One reason for this is that the roof bolting process involves some seven different steps as follows:
A. Drilling: PA1 B. Chemical Anchor: PA1 C. Roof Bolting: PA1 a rotatable holding means to hold a plurality of rods therein, PA1 a transport means cooperating with said holding means to move one rod at a time between said holding means and a tool which will use said rod to perform a mine operation,
1. loading drill steel into the rotational drive or drilling unit; PA2 2. drilling a rock surface; PA2 3. removing drill steel from the rotational drive or drilling unit; PA2 4. loading chemical anchor into the bored hole into a formation to be anchored; PA2 5. loading a roof bolt into the rotational drive or drilling unit; PA2 6. rotating the roof bolts so as to mix and thus set the chemical anchor; PA2 7. once chemical anchor has been secured, tightening the nut on the roof bolt to thereby finalise the roof bolting process. PA2 said holding means having a generally elongated shape and being able to rotate about a longitudinal axis of said shape so as to position one rod held by said holding means adjacent said transport means so that said transport means can transport said rod to said tool or position said holding means to receive a rod transported by said transport means from said tool; PA2 said transport means when fully retracted being substantially within a cylinder generated by the rotation of one of said rods about said longitudinal axis of said holding means.
Whilst there are at least seven steps in the process, the difficulty has been to replicate the actions of humans who attend to these seven steps.
One major difficulty has been replicating the actions of humans to load drill steels and roof bolts into the rotational drive or drilling units. A second major difficulty is the installation of the anchor chemicals into the bored surface of a formation to be anchored.
One attempt to solve these problems is disclosed in U.S. Pat. No. 4,229,124, published on Oct. 21, 1998. Disclosed in U.S. Pat. No. 4,229,124 is an automatic roof bolting system having a powered rotational drilling unit, a rotatable storage unit for resin; a powered rotational roof bolt installer; and a rotatable storage units to dispense roof bolts.
U.S. Pat. No. 4,229,124 has several disadvantages. One disadvantage is that two of the four components must be able to be lined up with a hole drilled by the drilling unit in circumstances which do not lend themselves to precise work. A second disadvantage is the need to provide two drive units which is expensive, requires additional controls and adds weight. For the system of U.S. Pat. No. 4,229,124 to operate, the four units must be able to rotate around a pivot, so as to align the drill unit, resin storage unit and roof bolt installer with the bore once it is drilled. Another difficulty with the system disclosed in U.S. Pat. No. 4,229,124 is that the use of the four units results in a very large footprint. Such a large footprint, together with a double sized footprint (to allow for rotation about the pivot) makes the system somewhat unsuitable for applications where multiple roof bolters are to work in the confined space of a mine entry.
It is an object of the present invention to ameliorate, at least in part, at least one disadvantages of the prior art.